Sony DV cam files won't play

[SPOOLIN]

I used my friends digital video camera at a race and when we load the vids to his computer, it plays them. They are .MPG files, but when i load them to my laptop(pc) or my imac(what i really want them to play on), i can't get them to play. the mac says "not a movie file" but i have other .mpg files that play fine on it. Its a sony digital video camera just 2 or 3 months old. Any ideas????

[SPOOLIN]

HELP